Systematic literature review and meta-analysis on preventing and controlling norovirus outbreaks on cruise ships, 1990 to 2020: calling for behaviour change strategies of travellers

BackgroundOutbreaks of norovirus gastroenteritis aboard cruise ships may affect a large number of people, debilitate vulnerable travellers, disrupt vacations and cause economic losses to the cruise ship industry.AimWe aimed to identify risk factors for norovirus outbreaks on cruise ships and assess the effectiveness of prevention and control measures.MethodsWe conducted a systematic literature review searching PubMed and Scopus databases as well as grey literature for articles and reports describing norovirus outbreaks on cruise ships between 1990 and 2020. We also performed a meta-analysis of norovirus prevalence in passengers and crew members.ResultsData from 45 outbreaks on 26 cruise ships from 1990 to 2020 were identified in 13 articles and five reports, with a weighted average of prevalence (attack rate) for passengers of 7% (95% confidence interval (CI): 5.00-9.00) and for crew of 2% (95% CI: 0.00-3.00). Person-to-person was the most frequent mode of transmission in 35 of the 45 outbreaks (in 14 the only mode and in 21 as part of multiple transmission routes). Having an ill cabin mate (OR = 38.70; 95% CI: 13.51-110.86) was the most common risk factor. Six outbreak investigations reported poor hygiene, while four reported satisfactory hygiene in the cruise setting. Behavioural risk factors among travellers were investigated in three of the 13 studies.ConclusionsThe findings indicate a need for behavioural interventions to improve personal hygiene, symptom reporting and compliance with isolation measures, and for reconsidering current isolation policies where symptomatic and healthy individuals are isolated in the same cabin.

Randomized, placebo-controlled, double-blinded study of prophylactic cranberries use in women with recurrent uncomplicated cystitis

BACKGROUND

Τhe adherence of p-fimbriated Escherichia coli (E. coli) to urothelial cells leading to recurrent urinary tract infections (rUTIs) may be prevented by proanthocyanidins (PACs) contained in American cranberries.

PURPOSE

The purpose of this clinical trial was to assess the clinical utility of prophylactic use of high-dose PACs daily in women with a history of rUTIs.

MATERIALS AND METHODS

172 adult women with a history of rUTIs, defined as ≥ 2 within a 6-month period or ≥ 3 within a 12-month period were enrolled and randomized in two groups to receive either Cysticlean™ 240 mg or placebo for a 12-month period. Urine samples, vaginal and rectal swabs were collected at initial and quarterly study visits. The primary study endpoints were the number of urinary tract infections (UTIs) and changes in Quality of Life (QoL), assessed by the 36-Item Short Form Survey (SF-36) questionnaire.

RESULTS

160 adult women of median age 40 years old (range 19-82) were finally analyzed in this randomized, placebo-controlled, double-blinded clinical trial. In response to intervention, the number of UTIs was significantly lower (Incidence rate ratio IRR 0.49, p < 0.001) and QoL was slightly improved. The numbers of E. coli isolates detected in vaginal (IRR 0.71, p value < 0.001) and in rectal swabs (IRR 0.87, p value < 0.001) were also significantly decreased. No adverse events were reported.

CONCLUSION

The daily use of Cysticlean™ 240 mg was associated with a reduction of UTIs and a prolongation of UTI-free survival compared to placebo treatment, supporting its use as prophylaxis in this patient population.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier NCT03032003.

Dynamics of Anti-SARS-CoV-2 IgA and IgG Responses and Their Protective Effect against Fatal Disease after Booster COVID-19 Vaccination

During the post-coronavirus disease (COVID-19) era, a primary question is whether booster vaccination is effective against severe COVID-19 and should be recommended, particularly to individuals at high risk for severe disease (i.e., the elderly or those with additional severe comorbidities). From December 2020 to February 2023, a cohort study was conducted to estimate IgG and IgA immunogenicity and the dynamics of booster mono- and bivalent COVID-19 mRNA vaccines in 260 individuals (male/female: 114/146, median age: 68 years, interquartile range (IQR) = 31) who initially received either mRNA (218) or adenovirus-vector-based vaccines (42). Participants were followed until the 90th day after the third booster dose. Our cohort study indicated a beneficial effect of booster vaccination on the magnitude of IgG and IgA severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies. We found that second and third booster doses were more protective than one against fatal disease (p = 0.031, OR 0.08). In conclusion, booster COVID-19 vaccination should be strongly recommended, especially to individuals at high risk for severe/fatal disease.

Innate Immune Gene Polymorphisms and COVID-19 Prognosis

COVID-19 is characterized by a heterogeneous clinical presentation and prognosis. Risk factors contributing to the development of severe disease include old age and the presence of comorbidities. However, the genetic background of the host has also been recognized as an important determinant of disease prognosis. Considering the pivotal role of innate immunity in the control of SARS-CoV-2 infection, we analyzed the possible contribution of several innate immune gene polymorphisms (including TLR2-rs5743708, TLR4-rs4986790, TLR4-rs4986791, CD14-rs2569190, CARD8-rs1834481, IL18-rs2043211, and CD40-rs1883832) in disease severity and prognosis. A total of 249 individuals were enrolled and further divided into five (5) groups, according to the clinical progression scale provided by the World Health Organization (WHO) (asymptomatic, mild, moderate, severe, and critical). We identified that elderly patients with obesity and/or diabetes mellitus were more susceptible to developing pneumonia and respiratory distress syndrome after SARS-CoV-2 infection, while the IL18-rs1834481 polymorphism was an independent risk factor for developing pneumonia. Moreover, individuals carrying either the TLR2-rs5743708 or the TLR4-rs4986791 polymorphisms exhibited a 3.6- and 2.5-fold increased probability for developing pneumonia and a more severe disease, respectively. Our data support the notion that the host's genetic background can significantly affect COVID-19 clinical phenotype, also suggesting that the IL18-rs1834481, TLR2-rs5743708, and TLR4-rs4986791 polymorphisms may be used as molecular predictors of COVID-19 clinical phenotype.

Molecular Analysis of Hot-Spot Regions of ACE2 and TMPRSS2 in SARS-CoV-2 "Invulnerable" Individuals

Background Coronavirus disease 2019 (COVID-19) is characterized by a wide clinical variability, ranging from acute illness that may require hospitalization and intensive care unit management to mild and even asymptomatic disease. A more exciting phenomenon is the presence of individuals who came into close contact with COVID-19 patients without prophylaxis but were never infected by SARS-CoV-2, even as an asymptomatic disease. Aims We describe four such "invulnerable" individuals and explore if they carry genetic defects in hot-spot regions of ACE2 and TMPRSS2 genes, which are responsible for virus entry into the host cells. Materials and methods Anti-S humoral and cellular immune responses were evaluated in the study participants through chemiluminescent microparticle immunoassay (CMIA) and enzyme-linked immunosorbent assay (ELISA) and interferon (IFN-γ) secretion measurement, respectively. Moreover, the hot-spot locations of ACE2 and TMPRSS2 were analyzed by polymerase chain reaction (PCR) sequencing in order to investigate potential genetic defects. Results No pathogenic genetic defects in ACE2 and TMPRSS2 were identified in the study participants. However, a functional polymorphism (rs12329760) located in exon 6 of the TMPRSS2 gene was detected in two of the four participants. In addition, it is worth noting that two individuals displayed adequate humoral and cellular immune responses after COVID-19 vaccination several months after their initial exposure to SARS-CoV-2. Conclusions We suggest that ACE2 and TMPRSS2 genes are not responsible for the "invulnerable" phenotype against COVID-19.

Measles Immunity Status of Greek Population after the Outbreak in 2017-2018: Results from a Seroprevalence National Survey

Accurate data on susceptibility rates against measles in the general population of Greece are scarce. Many studies have estimated the vaccination coverage, but none have calculated the nationwide immunity rate, including all age groups, against the measles virus. The purpose of our study was to determine the measles immunity status, especially after the latest outbreak in 2017-2018. In total, 3972 leftover blood samples were obtained during 2020-2021. They were collected from a nationwide laboratory network using a geographically stratified sampling strategy and were tested for the presence of measles-specific IgG antibodies. The overall crude seroprevalence was calculated to be 89.6% and the adjusted was 89.8% (95% CI: 88.8-90.8%). There was no statistically significant difference in seropositivity between sexes (p = 0.783). Higher immunity rates and antibody concentrations were found in older age groups ≥41 years old (94.9%, 95% CI: 93.7-95.9%, and 730.0 mIU/mL) in comparison with younger individuals aged 1-40 years old (83.4%, 95% CI: 81.6-85.7%, and 616.5 mIU/mL). Comparing the seroprevalence among the Nomenclature of Territorial Units for Statistics (NUTS 2), a statistically significant difference was estimated among them (<0.001). The two regions where higher measles incidence was observed during the 2017-2018 outbreak, Eastern Macedonia and Thrace, and Western Greece, were among the four regions with lower seropositivity (84.6%, 95% CI: 79.9-89.4%, and 85.9%, 95% CI: 81.4-90.4%, respectively). Our study showed a measles immunity gap that affects the younger age groups and makes a new measles outbreak likely. The enforcement of vaccination campaigns and addressing vaccine hesitancy could bridge it and achieve the required target of herd immunity.

The 2022 West Nile Virus Season in Greece; A Quite Intense Season

Since 2010, the West Nile virus (WNV) has been established in Greece. We describe the epidemiology of diagnosed human WNV infections in Greece with a focus on the 2022 season. During the transmission period, clinicians were sending samples from suspected cases for testing. Active laboratory-based surveillance was performed with immediate notification of diagnosed cases. We collected clinical information and interviewed patients on a timely basis to identify their place of exposure. Besides serological and molecular diagnostic methods, next-generation sequencing was also performed. In 2022, 286 cases of WNV infection were diagnosed, including 278 symptomatic cases and 184 (64%) cases with neuroinvasive disease (WNND); 33 patients died. This was the third most intense season concerning the number of WNND cases, following 2018 and 2010. Most (96%) cases were recorded in two regions, in northern and central Greece. The virus strain was a variant of previous years, clustering into the Central European subclade of WNV lineage 2. The 2022 WNV season was quite intense in Greece. The prompt diagnosis and investigation of cases are considered pivotal for the timely response, while the availability of whole genome sequences enables studies on the molecular epidemiology of the disease.

Nationwide Survey on Seasonal Influenza Vaccination among Health Care Workers during the COVID-19 Pandemic in Greece: Determinants, Barriers and Peculiarities

BACKGROUND

Seasonal influenza vaccination (SIV) of health care workers (HCWs) is critical in protecting patients' and HCWs' health. Our objective was to examine HCW SIV coverage and related determinants.

METHODS AND MATERIALS

A nationwide cross-sectional questionnaire survey was conducted among HCWs during the first half of 2021. The questionnaire (online or paper-based) included knowledge, attitude and practice questions regarding SIV, COVID-19 vaccines and vaccination.

RESULTS

Out of 6500 questionnaires administered, 2592 were completed (response rate: 39.9%). SIV coverage reached 69.4% (95% CI: 67.6-71.2%) based on self-reported vaccine uptake. Nurses and administrative staff were found to be more skeptical and have lower vaccine acceptance in comparison with physicians (aOR = 0.66 and aQR = 0.59, respectively). Other SIV hesitancy risk factors included working in secondary health care (aOR = 0.59) and working in northern Greece (aQR = 0.66). Determinants for SIV acceptance included being or living with high-risk people due to medical history (aOR = 1.84 and aOR = 1.46, respectively), positive attitudes towards routine vaccinations (aOR: 1.86), knowledge about COVID-19 vaccines (aOR = 1.53) and COVID-19 vaccine uptake (aOR = 3.45). The primary reason for SIV refusal was low risk perception (58.7%).

CONCLUSIONS

SIV coverage (2020/2021) was relatively high, but remained far from formal recommendations. Specific occupational groups were skeptical and low-risk perception was the main reason for vaccine refusal. Targeted policies should be developed and enforced.

Does tourism affect the long term course of COVID-19 pandemic in a country of destination? Evidence from a popular Greek island in 2020 where control measures were implemented

Greece opened its points of entry on July 1, 2020, with specific guidelines for travellers arriving by sea, air or land. The aim of this article is to examine the effect of tourism on the long term course of the Coronavirus Disease 2019 (COVID-19) pandemic during the pre-vaccination era (June to December 2020) on the popular Greek island of Crete. To achieve this, a cross-sectional serosurvey, repeated at monthly intervals, was conducted to compare the seroprevalence in Crete with seroprevalence in the mainland of Greece. Crete welcomed nearly 2,000,000 travellers during the 2020 summer season. Left-over serum samples were collected and obtained from public and private laboratories located in Greece, including the island of Crete. These samples were tested for the presence of anti-SARS-CoV-2 IgG antibodies. A total of 55,938 samples were collected, 3,785 of which originated from Crete. In Crete, the seroprevalence ranged between 0% (June 2020) and 2.58% (December 2020), while the corresponding seroprevalence in Greece was 0.19% and 10.75%, respectively. We identified 4.16 times lower seropositivity in Crete (2.58%) in comparison with the mainland of Greece (10.75%) during December 2020. Moreover, the monthly infection fatality rate (IFR) in Crete was calculated at 0.09%, compared with 0.21% in mainland Greece for December 2020. The island of Crete presented more than four times lower seroprevalence than the mainland of Greece, despite being a highly attractive tourist destination. This evidence supports the idea that tourism may not have affected the long term course of the COVID-19 pandemic in Greece. However, due to contradicting results from previous studies, further investigation is needed.

Winter survival of adults of two geographically distant populations of Aedes albopictus in a microclimatic environment of Athens, Greece

Overwintering capacity is a major step towards establishment of invasive mosquitoes from the tropics in temperate zone areas and one of the main elements determining next seasons' population size that regulates disease transmission of competent invasive vector species. The Asian tiger mosquito, Aedes albopictus (Skuse) (Diptera: Culiciidae) is an aggressive invasive species that has greatly expanded its geographical boundaries over the last few decades. The species' ability to induce photoperiodic-based egg diapause allows its overwintering in temperate regions, which favors its establishment in higher latitudes. In warmer temperate areas winter survival can be accomplished in the adult stage as well especially in human-made shelters. Aedes albopictus is already showing signs of adaptation to colder climates which may result in disease transmission in new areas. Although the Asian tiger mosquito has invaded Greece since 2003-4, little is known regarding its overwintering capacity in the country, especially as far as adults are regarded. We studied the survival of Ae. albopictus adults during winter in a protected shelter in Athens, the capital city of Greece. The study involved two geographically isolated populations originating from Chania (Crete, most southern part of Greece), and Palaio Faliro (Athens, Central Greece). We exposed different cohorts of F3 adults of the above two populations that emerged from field collected eggs to "winter condition" from November 2018 to beginning of January 2019. in a protected microclimatic environment. Adult mortality was recorded systematically until the death of the last individual in the cohort. Results demonstrated evidence of winter survival of adults for both populations. Longevity of both females and males of the Palaio Faliro population was longer than that of the Chania population for almost all installation dates. Survival curves, regardless of the date of installation, were steeper for females of the Chania population compared to those from Palaio Faliro. In conclusion, overwinter survival of both populations in the adult stage highlights the need for future studies, considering local and microclimatic condition that vary significantly between regions. Winter climatic conditions play vital role in adult survival of this highly important public health species concerning distribution limits and knowledge on winter survival of Ae. albopictus transmitted viruses.

Prevalence of rheumatoid arthritis in Greece: results from the national health examination survey EMENO

Rheumatoid arthritis (RA) is considered the most common form of autoimmune arthritis. The disease's prevalence is around 0.5-1% worldwide, but it seems to vary among different populations. The aim of this study was to estimate the prevalence of self-reported diagnosed RA in the general adult population in Greece. The data were derived from the Greek Health Examination Survey EMENO, a population-based survey performed between 2013 and 2016. Of the 6006 participants (response rate 72%), 5884 were eligible for this study. Prevalence estimates were calculated according to the study design. Prevalence of self-reported RA was estimated to be overall 0.5% (95% CI 0.4-0.7) being approximately three times higher in women than in men (0.7% vs 0.2%, p value = 0.004). A decrease in the prevalence of RA was observed in urban areas of the country. In contrast, higher disease rates were reported in individuals with lower socioeconomic status. Multivariable regression analysis showed that gender, age, and income were related to the occurrence of the disease. Osteoporosis and thyroid disease were the two comorbidities observed at statistically significant higher rates in individuals with self-reported RA. The prevalence of self-reported RA in Greece is similar to that reported in other European countries. Gender, age, and income are the main factors related to the disease's prevalence in Greece.

Wastewater Levels of Respiratory Syncytial Virus Associated with Influenza-like Illness Rates in Children-A Case Study in Larissa, Greece (October 2022-January 2023)

The emergence of the COVID-19 pandemic has led to significant progress in the field of wastewater-based surveillance (WBS) of respiratory pathogens and highlighted its potential for a wider application in public health surveillance. This study aimed to evaluate whether monitoring of respiratory syncytial virus (RSV) in wastewater can provide a comprehensive picture of disease transmission at the community level. The study was conducted in Larissa (Central Greece) between October 2022 and January 2023. Forty-six wastewater samples were collected from the inlet of the wastewater treatment plant of Larissa and analyzed with a real-time reverse transcription polymerase chain reaction (RT-PCR) based method. RSV and SARS-CoV-2 wastewater viral loads (genome copies/100,000 inhabitants) were analyzed against sentinel surveillance data on influenza-like illness (ILI) to identify potential associations. Univariate linear regression analysis revealed that RSV wastewater viral load (lagged by one week) and ILI notification rates in children up to 14 years old were strongly associated (std. Beta: 0.73 (95% CI: 0.31-1.14), p = 0.002, R2 = 0.308). A weaker association was found between SARS-CoV-2 viral load and ILI rates in the 15+ age group (std. Beta: 0.56 (95% CI: 0.06-1.05), p = 0.032, R2 = 0.527). The results support the incorporation of RSV monitoring into existing wastewater-based surveillance systems.

Development of Toehold Switches as a Novel Ribodiagnostic Method for West Nile Virus

West Nile virus (WNV) is an emerging neurotropic RNA virus and a member of the genus Flavivirus. Naturally, the virus is maintained in an enzootic cycle involving mosquitoes as vectors and birds that are the principal amplifying virus hosts. In humans, the incubation period for WNV disease ranges from 3 to 14 days, with an estimated 80% of infected persons being asymptomatic, around 19% developing a mild febrile infection and less than 1% developing neuroinvasive disease. Laboratory diagnosis of WNV infection is generally accomplished by cross-reacting serological methods or highly sensitive yet expensive molecular approaches. Therefore, current diagnostic tools hinder widespread surveillance of WNV in birds and mosquitoes that serve as viral reservoirs for infecting secondary hosts, such as humans and equines. We have developed a synthetic biology-based method for sensitive and low-cost detection of WNV. This method relies on toehold riboswitches designed to detect WNV genomic RNA as transcriptional input and process it to GFP fluorescence as translational output. Our methodology offers a non-invasive tool with reduced operating cost and high diagnostic value that can be used for field surveillance of WNV in humans as well as in bird and mosquito populations.

Seroprevalence of anti-SARS-CoV-2 antibodies among children and their parents in Greece

School closures were enforced as measures to restrain the COVID-19 pandemic, based on the assumption that young children may play a key role in SARS-CoV-2 spread. This study aims to determine the prevalence of SARS-CoV-2 IgG antibodies in children and corresponding parents, in order to improve surveillance and estimate the prevalence of asymptomatic or subclinical COVID-19 cases. A prospective multicenter study was conducted between March and June 2021 in Greece. Children admitted to the hospital or examined in outpatient clinics for reasons other than COVID-19 and their parents were tested for anti-Spike SARS-CoV-2 IgG in serum. A questionnaire about clinical and demographic data was completed. The study included 823 participants: 427 children and 396 corresponding parents. The overall seroprevalence was 16.4% in parents and 13.8% in children. Among families with ≥ 1 seropositive child or parent, the combination of a seropositive parent and a corresponding seronegative child was 29.6%, a seronegative parent and a corresponding seropositive child was 24.7%, and a seropositive child with a corresponding seropositive parent was 45.7%. Age, level of education, and school or work attendance were not significantly associated with increased seropositivity. On the contrary, ethnic minority of Roma, close contact with known COVID-19 case, previous symptoms consistent with COVID-19, and mass gatherings were risk factors for seropositivity.

CONCLUSION

The spread of SARS-CoV-2 during a period of lockdown in Greece was low in children and comparable to adults most likely due to intrafamilial transmission. Accordingly, it is unlikely that children have boosted virus transmission.

WHAT IS KNOWN

• In the earliest months of the pandemic, it was demonstrated that children had significantly lower seroprevalence rates than the older age groups, due to the fact that children had decreased exposure to the virus, because of early public health interventions, such as school and day care closure. • Later, further studies reported that children have similar incidence rate of SARS-CoV-2 infection compared to adults in households and community settings.

WHAT IS NEW

• In this seroprevalence study, the spread of SARS-CoV-2 infection during a period of lockdown in Greece with the predominance of the Alpha-variant was particularly low in children and comparable to adults, most likely due to intrafamilial transmission. • These study findings will be useful for decisions regarding non-pharmaceutical interventions during the pandemic, and especially, to guide in designing and implementing appropriate containment measures for schools and social gatherings.

Behavioral and Cultural Insights, a Nationwide Study Based on Repetitive Surveys of WHO Behavioral Insights Tool in Greece Regarding COVID-19 Pandemic and Vaccine Acceptance

Monitoring behavioral and cultural insights during the pandemic is a useful tool to identify factors related to COVID-19 vaccine acceptance and confront the pandemic’s vast impact. Data were collected using a questionnaire designed according to the “survey tool and guidance” provided by the World Health Organization (WHO). Surveys were conducted by a market research company for five consecutive months, with a sample of 1000 individuals recruited per survey. Vaccination acceptance increased from 55.2% to 67.2%, while the percentage of undecisive individuals decreased from 16.3% to 10.6%. The proportion of vaccine resistant participants remained relatively steady (25−30%). Knowledge about the pandemic and compliance with preventive measures was high (>90%). Factors associated with vaccination included: Increased age, male gender, influenza vaccination, following authorities’ recommendations, being informed by HCWs or formal information sources, care for others, concern about the country’s economic recession and health system overload. Pandemic fatigue was reflected across the surveys, indicated by a decrease in the intention to self-isolate and remain at home when ill. Despite the decrease of undecisive individuals, a firm core of vaccine resistant individuals may be responsible for the relatively lower vaccine coverage compared to northern EU countries. Study results could be useful for developing approaches tailored to a reluctant population.

SARS-CoV-2 wastewater monitoring using a novel PCR-based method rapidly captured the Delta-to-Omicron ΒΑ.1 transition patterns in the absence of conventional surveillance evidence

Conventional SARS-CoV-2 surveillance based on genotyping of clinical samples is characterized by challenges related to the available sequencing capacity, population sampling methodologies, and is time, labor, and resource-demanding. Wastewater-based variant surveillance constitutes a valuable supplementary practice, since it does not require extensive sampling, and provides information on virus prevalence in a timely and cost-effective manner. Consequently, we developed a sensitive real-time RT-PCR-based approach that exclusively amplifies and quantifies SARS-CoV-2 genomic regions carrying the S:Δ69/70 deletion, indicative of the Omicron BA.1 variant, in wastewater. The method was incorporated in the analysis of composite daily samples taken from the main Wastewater Treatment Plant of Thessaloniki, Greece, from 1 December 2021. The applicability of the methodology is dependent on the epidemiological situation. During Omicron BA.1 global emergence, Thessaloniki was experiencing a massive epidemic wave attributed solely to the Delta variant, according to genomic surveillance data. Since Delta does not possess the S:Δ69/70, the emergence of Omicron BA.1 could be monitored via the described methodology. Omicron BA.1 was detected in sewage samples on 19 December 2021 and a rapid increase of its viral load was observed in the following 10-day period, with an estimated early doubling time of 1.86 days. The proportion of the total SARS-CoV-2 load attributed to BA.1 reached 91.09 % on 7 January, revealing a fast Delta-to-Omicron transition pattern. The detection of Omicron BA.1 subclade in wastewater preceded the outburst of reported (presumable) Omicron cases in the city by approximately 7 days. The proposed wastewater surveillance approach based on selective PCR amplification of a genomic region carrying a deletion signature enabled rapid, real-time data acquisition on Omicron BA.1 prevalence and dynamics during the slow remission of the Delta wave. Timely provision of these results to State authorities readily influences the decision-making process for targeted public health interventions, including control measures, awareness, and preparedness.

SARS-CoV-2 wastewater monitoring using a novel PCR-based method rapidly captured the Delta-to-Omicron ΒΑ.1 transition patterns in the absence of conventional surveillance evidence

Conventional SARS-CoV-2 surveillance based on genotyping of clinical samples is characterized by challenges related to the available sequencing capacity, population sampling methodologies, and is time, labor, and resource-demanding. Wastewater-based variant surveillance constitutes a valuable supplementary practice, since it does not require extensive sampling, and provides information on virus prevalence in a timely and cost-effective manner. Consequently, we developed a sensitive real-time RT-PCR-based approach that exclusively amplifies and quantifies SARS-CoV-2 genomic regions carrying the S:Δ69/70 deletion, indicative of the Omicron BA.1 variant, in wastewater. The method was incorporated in the analysis of composite daily samples taken from the main Wastewater Treatment Plant of Thessaloniki, Greece, from 1 December 2021. The applicability of the methodology is dependent on the epidemiological situation. During Omicron BA.1 global emergence, Thessaloniki was experiencing a massive epidemic wave attributed solely to the Delta variant, according to genomic surveillance data. Since Delta does not possess the S:Δ69/70, the emergence of Omicron BA.1 could be monitored via the described methodology. Omicron BA.1 was detected in sewage samples on 19 December 2021 and a rapid increase of its viral load was observed in the following 10-day period, with an estimated early doubling time of 1.86 days. The proportion of the total SARS-CoV-2 load attributed to BA.1 reached 91.09 % on 7 January, revealing a fast Delta-to-Omicron transition pattern. The detection of Omicron BA.1 subclade in wastewater preceded the outburst of reported (presumable) Omicron cases in the city by approximately 7 days. The proposed wastewater surveillance approach based on selective PCR amplification of a genomic region carrying a deletion signature enabled rapid, real-time data acquisition on Omicron BA.1 prevalence and dynamics during the slow remission of the Delta wave. Timely provision of these results to State authorities readily influences the decision-making process for targeted public health interventions, including control measures, awareness, and preparedness.

Machine-Learning-Assisted Analysis of TCR Profiling Data Unveils Cross-Reactivity between SARS-CoV-2 and a Wide Spectrum of Pathogens and Other Diseases

During the last two years, the emergence of SARS-CoV-2 has led to millions of deaths worldwide, with a devastating socio-economic impact on a global scale. The scientific community's focus has recently shifted towards the association of the T cell immunological repertoire with COVID-19 progression and severity, by utilising T cell receptor sequencing (TCR-Seq) assays. The Multiplexed Identification of T cell Receptor Antigen (MIRA) dataset, which is a subset of the immunoACCESS study, provides thousands of TCRs that can specifically recognise SARS-CoV-2 epitopes. Our study proposes a novel Machine Learning (ML)-assisted approach for analysing TCR-Seq data from the antigens' point of view, with the ability to unveil key antigens that can accurately distinguish between MIRA COVID-19-convalescent and healthy individuals based on differences in the triggered immune response. Some SARS-CoV-2 antigens were found to exhibit equal levels of recognition by MIRA TCRs in both convalescent and healthy cohorts, leading to the assumption of putative cross-reactivity between SARS-CoV-2 and other infectious agents. This hypothesis was tested by combining MIRA with other public TCR profiling repositories that host assays and sequencing data concerning a plethora of pathogens. Our study provides evidence regarding putative cross-reactivity between SARS-CoV-2 and a wide spectrum of pathogens and diseases, with M. tuberculosis and Influenza virus exhibiting the highest levels of cross-reactivity. These results can potentially shift the emphasis of immunological studies towards an increased application of TCR profiling assays that have the potential to uncover key mechanisms of cell-mediated immune response against pathogens and diseases.

Prevalence and Predictors of COVID-19 Vaccination Acceptance among Greek Health Care Workers and Administrative Officers of Primary Health Care Centers: A Nationwide Study Indicating Aspects for a Role Model

Background: Τhe study aims to identify factors associated with COVID-19 vaccine acceptance and to investigate knowledge and perceptions of Primary Health Care Centers (PHCC) personnel, who acted as pioneers in the national COVID-19 vaccination strategy. Methods and Materials: A nationwide cross-sectional survey was conducted by distributing an online anonymous questionnaire comprising 25 questions during the first semester of 2021. Results: Approximately 85.3% of the 1136 respondents (response rate 28.4%) were vaccinated or intended to be. The acceptance of seasonal flu vaccine (aOR: 3.29, 95%CI: 2.08−5.20), correct COVID-19 vaccine knowledge (aOR: 8.37, 95%CI: 4.81−14.59) and lack of concern regarding vaccine novelty (aOR: 6.18, 95%CI: 3.91−9.77) were positively correlated with vaccine acceptance. Vaccinated respondents were more likely to be physicians (aOR: 2.29, 95%CI: 1.03−5.09) or administrative staff (aOR: 2.65, 95%CI: 1.18−5.97) compared to nursing stuff. Reasons for vaccine hesitancy included inadequate information (37.8%) and vaccine safety (31.9%). Vaccine acceptance was strongly correlated (Spearman’s correlation coefficient r = 0.991, p < 0.001) between PHCC personnel and the general population of each health district. Conclusions: COVID-19 vaccine acceptance among PHCC personnel in Greece was comparably high, but specific groups (nurses) were hesitant. As the survey’s target population could serve as a role model for the community, efforts should be made to improve COVID-19 vaccine acceptance.

Study Protocol: The Feeding Exercise Randomized Trial among Overweight and Obese Adolescents in Greece

Background: This paper describes the study protocol used in the Feeding Exercise Clinical Trial in Adolescents in the region of Larissa in Greece, a randomized controlled clinical trial, among overweight/obese adolescents.

Methods: The main aim of the study was to comparatively evaluate the effectiveness of 2 different clinical interventions among 12 to 18-year-old overweight and obese adolescents. The first group participated in an exercise program and the second group in a combined dietary and exercise program. The third group was the control group. The study was conducted between 2014 and 2015. All adolescents aged 12 to 18 years old from public schools of Larisa and also their parents asked to participate. The effects of the intervention program will be analyzed by repeated-measures analysis of variance or the Friedman test. Changes in lifestyle behaviors from the baseline to the end of the intervention will be assessed using a chi-square test for categorical variables. A Pearson or a Spearman correlation coefficient and a linear regression analysis will be performed to explore any associations between quantitative variables. The following parameters were measured among adolescents: height, weight, body mass index, waist circumference, systolic and diastolic pressure, pulse rate, dietary and exercise habits of the adolescents and their parents.

Conclusion: This is the first clinical trial in Greece investigating the impact of clinical interventions on obesity among adolescents. It is expected that the results will provide useful insights into the effectiveness of clinical interventions among overweight and obese adolescents in Greece.

SARS-CoV-2 Sero-Surveillance in Greece: Evolution over Time and Epidemiological Attributes during the Pre-Vaccination Pandemic Era

Background: Nation-wide SARS-CoV-2 seroprevalence surveys provide valuable insights into the course of the pandemic, including information often not captured by routine surveillance of reported cases. Methods: A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between March and December 2020. It was designed as a cross-sectional survey repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. Results: Of 55,947 serum samples collected, 705 (1.26%) were found positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (9.09%) observed in December 2020. Highest seropositivity levels were observed in the “0–29” and “30–49” year age groups. Seroprevalence increased with age in the “0–29” age group. Highly populated metropolitan areas were characterized with elevated seroprevalence levels (11.92% in Attica, 12.76% in Thessaloniki) compared to the rest of the country (5.90%). The infection fatality rate (IFR) was estimated at 0.451% (95% CI: 0.382–0.549%) using aggregate data until December 2020, and the ratio of actual to reported cases was 9.59 (7.88–11.33). Conclusions: The evolution of seroprevalence estimates aligned with the course of the pandemic and varied widely by region and age group. Young and middle-aged adults appeared to be drivers of the pandemic during a severe epidemic wave under strict policy measures.

Prevalence and characteristics of Listeria monocytogenes in meat, meat products, food handlers and the environment of the meat processing and the retail facilities of a company in Northern Greece

In this study, we investigated the incidence of Listeria monocytogenes in the receiving meat, the meat products, the personnel and the environment of a vertically integrated company in Northern Greece owing a processing plant and three trading facilities. A total of 303 samples were examined from the receiving raw meat, raw meat preparations, ready-to-eat meat products, processing surfaces and the environment of these facilities as well as the food handlers' hands and nasal cavities. MALDI-TOF MS was used for Listeria identification; from the 22 (7·26%) positive to Listeria spp. isolates, 12 (3·96%) identified as L. monocytogenes, eight (2·64%) as Listeria innocua and two (0·66%) as Listeria welshimeri. Molecular serotyping of L. monocytogenes isolates by multiplex PCR revealed 11 strains belonging to serogroup IIa (1/2a and 3a) and one to IIc (1/2c and 3c). The assay for the detection of the virulence-associated genes revealed eight isolates carrying all the examined genes (inlA, inlB, inlC, plcA, prfA, actA, hlyA and iap) and four carrying all except the actA gene. Eleven (91·7%) of the isolates showed a strong ability to form biofilm. All isolates were multidrug resistant. The MALDI-TOF Main Spectrum Profile (MSPs), revealed three clusters: one with five isolates (four from environmental samples and one from a food handler), one with five isolates (all from environmental samples) and one with two isolates (both from raw meat products). MALDI-TOF MS seems to be a reliable tool for the identification of niches and contamination routes in processing plants, contributing also to the evaluation and improvement of the applied preventive measures to control L. monocytogenes.

What is next? Vision statement and reflections for sustaining project outcomes in a possibly post-pandemic era

Introduction

The ongoing COVID-19 pandemic has demonstrated the importance in strengthening cooperation and coordinated action of Member States (MS) to improve preparedness and response capacities at points of entry (PoE). This emphasizes the need for perpetuating the work of EU HEALTHY GATEWAYS (EU HG) and the availability of this cross-European network to transfer lessons learned for future public health threats.

Methods

An interdisciplinary sustainability working group identified options for continuity of activities at EU level and provided a template national sustainability plan to be adapted by MS based on national needs and priorities.

Results

Since the beginning of the pandemic EU HG provided 37 consultations to MS, developed 15 advice documents, delivered training courses, produced a study on preparedness and response at PoE and developed the EU digital Passenger Locator Form (EUdPLF) system. A European web-based network for PoE was developed including discussion forums, e-learning platform, searchable network of professionals' at PoE registry, bibliographies, web-based training resources and best practice catalogues. Overall, the 533 inspectors in the EU SHIPSAN INFORMATION SYSTEM (EU SIS) recorded 29268 IHR (International Health Regulations) certificates, followed up 69 public health events via the communication network for EU ports, and recorded >4600 hygienic deficiencies.

Conclusions

EU HG has a holistic approach, supporting operations on local, regional, national and European level and by taking into account all transport sectors. The web-based systems and capacity building activities support EU Decision 1082/2013/EU for serious cross-border health threats and the EUdPLF supports implementing Decision (EU) 2017/253 for the contact tracing of passengers identified through PLFs. Adoption of components of EU SIS will support implementation of Regulation (EU) 2019/1239 which includes the provision of a common ship sanitation database.

Sharing of public health information in response to maritime outbreaks – report from an exercise conducted at a European level

Background

Inter-country communication and structured information flow is of major importance in outbreak management potentially affecting more than one country, particularly in case of a public health event of international concern. Though there are established communication systems in European Member States (MS), public health events in the maritime sector challenge authorities and stakeholders.

Methods

Guidelines for inter-country communication developed by the joint action were tested via a 1-day web-based multi-sectorial, discussion-based table-top exercise (TTE) for ports at European level. Two outbreak scenarios (gastroenteritis and COVID-19) on passenger ships in separate regions (Mediterranean, North Sea) were acted out consecutively.

Results

Thirty participants and 63 observers from 20 MS, cruise ships, international and European institutions took part in the TTE. The TTE identified two different information flows: (1) authorities at local level implementing public health measures on ships share information with the next and previous ports of call, either directly or via national level authorities using different platforms depending on the event without clearly predefined criteria and (2) the ship captain sends health information to the next port of call (via the National Single Window or Email or Telephone or other means). Relying on communication via emails and telephones however, has limitations: a) limited access, b) no central data storage, c) historical data unavailable. Lack of communication channels for feedback to the ship and of coordinating and closing an event was evident.

Conclusions

A successfully conducted European TTE in maritime outbreak scenarios identified lack of clear international communication as communication channels were not always clear and depend on local/national conditions. There is potential for improving international communication. Guidelines for inter-country communication in this setting may help enhance communication practice.

European Union Digital Passenger Locator Form System (EUdPLF) development

Introduction

Passenger Locator Forms (PLFs) are used by public health authorities to facilitate international contact tracing. Digital PLFs (dPLF) allows for easier, more rapid data collection and exchange between stakeholders, making international contact tracing more effective and efficient. In response to COVID-19, EU HEALTHY GATEWAYS developed a common European Union digital Passenger Locator Form System (EUdPLF) for all transport sectors (aircrafts, cruise ships/ferries and ground transport).

Methods

A working group was established consisting of 9 EUMS, EASA, EMSA, ECDC, IATA, ERA, CLIA EUROPE. A minimum mandatory dataset was developed. Personal data protection procedures and security measures were implemented. Interconnection of EUdPLF with the EASA exchange platform allowing exchange of data between MS with national dPLF and MS using the EUdPLF was completed. Pilot testing was conducted with four MS for the air and ferry sector.

Results

The EUdPLF system developed consists of a multilingual website being the first point of information for users and the EUdPLF app which is the web app for completion of the dPLF. One dPLF is completed per family/group, a QR code is generated and dPLF is sent to the passenger's email. Pilot testing generated 1013 PLFs submissions and 1450 passenger registrations. Feedback received was positive and used to improve user experience. To date, Italy is officially using the EUdPLF for all arriving passengers for all modes of transport. France, Slovenia, Lithuania and Austria are finalising practicalities before official use and testing of the system is ongoing with other MS.

Conclusions

EUdPLF provides multilingual, user-friendly, secure and GDPR compliant single entry point and database for the collection of PLFs, flexible to be customised to the MS needs and to be connected to external systems e.g. check-in system of transport operators, vaccination/testing/certificate information systems of each MS.

Prevalence of tobacco smoking and association with other unhealthy lifestyle risk factors in the general population of Greece: Results from the EMENO study

INTRODUCTION

The EMENO (National Morbidity and Risk Factors) survey is one of the first and most representative population-based surveys in Greece due to its study design and sampling procedure. We aimed to estimate the prevalence of smoking, secondhand smoking (SHS) and their potential associations with other socioeconomic and unhealthy lifestyle risk factors.

METHODS

EMENO is a cross-sectional health status survey conducted in Greece from May 2013 to June 2016. The survey was performed using face-to-face interviews and enrolled 6006 adults. Data were collected through questionnaires administered by trained interviewers. Current smoking (CS) and SHS were based on self-reporting. Analysis accounted for study design.

RESULTS

Information on smoking was available for 5862 individuals (97.6%). Overall, 37.8% were current and 16.1% former smokers. More males (44.3%) than females (31.6%) were current smokers. CS increased during adulthood and declined sharply in the elderly (p<0.001). Smoking initiation by the age of 17 years was reported by 48.7% of males and 36.2% of females. Multivariable analysis showed that higher alcohol consumption (>7 glasses/ week, OR=2.52; 95% CI: 1.97–3.23) and lower education level in men were positively associated with ever smoking. Moreover, women aged >35 years and respondents with low adherence to the Mediterranean diet (MD) (high/ low, OR= 0.35; 95% CI: 0.21–0.58) had higher odds to be current smokers than former smokers. Finally, the overall prevalence of exposure to SHS at work, home and public places was 38.8%, 30% and 44.6 %, respectively.

CONCLUSIONS

Unhealthy lifestyles of smokers, increased rates of CS in vulnerable groups, such as females and young adults, and early age of smoking initiation constitute alarming public health issues in Greece.

MBL deficiency-causing B allele (rs1800450) as a risk factor for severe COVID-19

The COVID-19 pandemic represents one of the greatest challenges in modern medicine. The disease is characterized by a variable clinical phenotype, ranging from asymptomatic carriage to severe and/or critical disease, which bears poor prognosis and outcome because of the development of severe acute respiratory distress syndrome (SARS) requiring ICU hospitalization, multi-organ failure and death. Therefore, the determination of risk factors predisposing to disease phenotype is of outmost importance. The aim of our study was to evaluate which predisposing factors, including MBL2 genotyping, affected clinical phenotype in 264 COVID-19 patients. We demonstrated that older age along with underlying comorbidities, primarily obesity, chronic inflammatory disorders and diabetes mellitus, represent the most important risk factors related to hospitalization, the development of pneumonia and SARS. Moreover, we found that the presence of the MBL deficiency-causing B allele (rs1800450) was significantly associated with almost 2-fold increased risk for developing pneumonia and requiring hospitalization, suggesting its usage as a molecular predictor of severe disease in SARS-CoV-2 infected individuals.

Effects of Selection to Diflubenzuron and Bacillus thuringiensis Var. Israelensis on the Overwintering Successes of Aedes albopictus (Diptera: Culicidae)

Aedes albopictus is an invasive mosquito species responsible for local transmission of chikungunya and dengue viruses in Europe. In the absence of available treatments, insecticides-based control remains one of the most important viable strategies to prevent emerging problems. Diflubenzuron (DFB) and Bacillus thuringiensis var. israelensis (Bti) are among the most commonly used larvicides for Ae. albopictus control with consequent concerns for the potential development of resistance. Studies on the resistance emergence in Ae. albopictus and its persistence in the wild to both DFB and Bti are essential for the efficient and sustainable planning of the control programmes. In this context, larvae from a recently laboratory established population were subjected to increasing selective pressure for nine successive generations using both DFB and Bti. The resistance levels and the overwintering success of the selected populations relative to control (colonies that received no selection) were determined. Results revealed an 8.5- and 1.6-fold increase on the resistance levels following selection with DFB and Bti, respectively. The selection process to both larvicides had no apparent impacts on the overwintering capability relative to control, suggesting the successful persistence of the selected individuals in the wild on an annual base.

Low seropositivity for SARS-CoV-2 antibodies among healthcare workers after the first COVID-19 pandemic wave in Greece

Objectives

To estimate the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seropositivity among healthcare workers (HCWs) in Greece and to identify high-risk groups in healthcare facilities.

Study design

The study design used in this study is a nationwide cross-sectional study.

Methods

Data were collected from 1 June to 9 July 2020. HCWs in the Greek National Health System were offered a free SARS-CoV-2 IgG antibody test, regardless of symptoms.

Results

Overall, 379 of 57,418 HCWs (0.66%, 95% confidence interval [CI]: 0.59–0.73) were positive for SARS-CoV-2 antibodies. The adjusted overall seroprevalence was 0.43% (95% CI: 0.35–0.51). We found that HCWs in non-reference hospitals for COVID-19 (odds ratio [OR]: 1.81, 95% CI: 1.23–2.64; P = 0.002) and reference hospitals for COVID-19 (OR: 1.66, 95% CI: 1.06–2.58; P = 0.03) were more likely to be seropositive than HCWs in primary care centres. Regarding professions, nurses (OR: 1.45, 95% CI: 1.07–1.98; P = 0.02), physicians (OR: 1.43, 95% CI: 1.06–1.93; P = 0.02), and administrative, cleaning and security staff (OR: 1.50, 95% CI: 1.09–2.06; P = 0.01) had a statistically higher chance of having a positive serology than laboratory employees.

Conclusions

The adjusted overall seroprevalence found in this study indicates a very low prevalence of SARS-CoV-2 among HCWs in Greece. This result is in line with the low incidence of COVID-19 during the first wave of the pandemic and is a direct benefit from the early implementation of lockdown.

Wastewater monitoring as a supplementary surveillance tool for capturing SARS-COV-2 community spread. A case study in two Greek municipalities

A pilot study was conducted from late October 2020 until mid-April 2021, aiming to examine the association between SARS-CoV-2 RNA concentrations in untreated wastewater and recorded COVID-19 cases in two Greek municipalities. A population of Random Forest and Linear Regression Machine Learning models was trained and evaluated incorporating the concentrations of SARS-CoV-2 RNA in 111 wastewater samples collected from the inlets of two Wastewater Treatment Plants, along with physicochemical parameters of the wastewater influent. The model's predictions were adequately associated with the 7-day cumulative cases with the correlation coefficients (after 5-fold cross validation) ranging from 0.754 to 0.960 while the mean relative errors ranged from 30.42% to 59.46%. Our results provide indications that wastewater-based predictions can be applied in diverse settings and in prolonged time periods, although the accuracy of these predictions may be mitigated. Wastewater-based epidemiology can support and strengthen epidemiological surveillance.

Molecular Epidemiology of SARS-CoV-2 in Greece Reveals Low Rates of Onward Virus Transmission after Lifting of Travel Restrictions Based on Risk Assessment during Summer 2020

The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly during the first months of 2020 and continues to expand in multiple areas across the globe. Molecular epidemiology has provided an added value to traditional public health tools by identifying SARS-CoV-2 clusters or providing evidence that clusters based on virus sequences and contact tracing are highly concordant. Our aim was to infer the levels of virus importation and to estimate the impact of public health measures related to travel restrictions to local transmission in Greece. Our phylogenetic and phylogeographic analyses included 389 full-genome SARS-CoV-2 sequences collected during the first 7 months of the pandemic in Greece and a random collection in five replicates of 3,000 sequences sampled globally, as well as the best hits to our data set identified by BLAST. Phylogenetic trees were reconstructed by the maximum likelihood method, and the putative source of SARS-CoV-2 infections was inferred by phylogeographic analysis. Phylogenetic analyses revealed the presence of 89 genetically distinct viruses identified as independent introductions into Greece. The proportion of imported strains was 41%, 11.5%, and 8.8% during the three periods of sampling, namely, March (no travel restrictions), April to June (strict travel restrictions), and July to September (lifting of travel restrictions based on thorough risk assessment), respectively. The results of phylogeographic analysis were confirmed by a Bayesian approach. Our findings reveal low levels of onward transmission from imported cases during summer and underscore the importance of targeted public health measures that can increase the safety of international travel during a pandemic. IMPORTANCE Our study based on current state-of-the-art molecular epidemiology methods suggests that virus screening and public health measures after the lifting of travel restrictions prevented SARS-CoV-2 onward transmission from imported cases during summer 2020 in Greece. These findings provide important data on the efficacy of targeted public health measures and have important implications regarding the safety of international travel during a pandemic. Our results can provide a roadmap about prevention policy in the future regarding the reopening of borders in the presence of differences in vaccination coverage, the circulation of the virus, and the presence of newly emergent variants across the globe.

The Presence of Fungal and Parasitic Infections in Substances of Human Origin and Their Transmission via Transfusions and Transplantations: Protocol for Two Systematic Reviews

Background

The European Union Directives stipulate mandatory tests for the presence of any infections in donors and donations of substances of human origin (SoHO). In some circumstances, other pathogens, including fungi and parasites, may also pose a threat to the microbial safety of SoHO.

Objective

The aim of the two systematic reviews is to identify, collect, and evaluate scientific evidence for the presence of fungal and parasitic infections in donors and donations of SoHO, and their transmission via transfusion and transplantation.

Methods

An algorithmic search, one each for fungal and parasitic disease, was applied to 6 scientific databases (PubMed, EMBASE, Web of Science, Scopus, Cochrane Library [trials], and CINAHL). Additionally, manual and algorithmic searches were employed in 15 gray literature databases and 22 scientific organization websites. The criteria for eligibility included peer-reviewed publications and peer-reviewed abstract publications from conference proceedings examining the prevalence, incidence, odds ratios, risk ratios, and risk differences for the presence of fungi and parasites in donors and SoHO donations, and their transmission to recipients. Only studies that scrutinized the donors and donations of human blood, blood components, tissues, cells, and organs were considered eligible. Data extraction from eligible publications will be performed independently by two reviewers. Data synthesis will include a qualitative description of the studies lacking evidence suitable for a meta-analysis and a random or fixed-effect meta-analysis model for quantitative data synthesis.

Results

This is an ongoing study. The systematic reviews are funded by the European Centre for Disease Prevention and Control, and the results are expected to be presented by the end of 2021.

Conclusions

The systematic reviews will provide the basis for developing a risk assessment for fungal and parasitic disease transmission via SoHO.

Trial Registration

PROSPERO International Prospective Register of Systematic Reviews CRD42020160090; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020160090 ; PROSPERO International Prospective Register of Systematic Reviews CRD42020160110; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020160110

International Registered Report Identifier (IRRID)

DERR1-10.2196/25674

Assessing training needs in infectious disease management at major ports, airports and ground-crossings in Europe

BACKGROUND

The implementation of core capacities as stated in the International Health Regulations (IHR) is far from complete, and, as the COVID-19 pandemic shows, the spreading of infectious diseases through points of entry (POEs) is a serious problem. To guide training and exercises, we performed a training needs assessment on infectious disease management among professionals at European POE.

METHODS

We disseminated a digital questionnaire to representatives of designated airports, ports, and ground-crossings in Europe. Topics were derived from the IHR core capacities for POEs. Based on the importance (4-point Likert scale) and training needs (4-point Likert scale), we identified the topics with the highest priority for training. These results were put in further perspective using prior experience (training < 3 year, exercise < 5 years, events < 5 years). Also, preferences for training methodologies were assessed.

RESULTS

Fifty questionnaires were included in the analyses, representing 50 POEs from 19 European countries. Importance is high for 26/30 topics, although scores widely vary among respondents. Topics with a high training need (16/30) are amongst others the handling of ill travelers; using and composing the public health emergency contingency plan, and public health measures. Respondents from ports and airports attribute equal importance to most topics, but respondents from ports showed higher training needs on 75% of the topics. POEs are unevenly and generally little experienced. The most preferred training methods were presentations. Simulation is the preferred methodology for training the handling of ill or exposed travelers.

CONCLUSIONS

The European workforce at designated ports, airports and ground-crossings has a different level of experience and perceives varying importance of the topics assessed in our study. We identified the topics on which training is required. We call for European collaboration between POEs to agree upon the importance of infectious disease management, and to jointly build a trained and prepared workforce that is ready to face the next crisis.

Repeated Leftover Serosurvey of SARS-CoV-2 IgG Antibodies in Greece, May to August 2020

A serosurvey of IgG antibodies against SARS-CoV-2 was conducted in Greece between May and August 2020. It was designed as a cross-sectional survey and was repeated at monthly intervals. The leftover sampling methodology was used and a geographically stratified sampling plan was applied. Of 20,110 serum samples collected, 89 (0.44%) were found to be positive for anti-SARS-CoV-2 antibodies, with higher seroprevalence (0.35%) observed in May 2020. The highest seroprevalence was primarily observed in the "30-49" year age group. Females presented higher seroprevalence compared to males in May 2020 (females: 0.58% VS males: 0.10%). This difference reversed during the study period and males presented a higher proportion in August 2020 (females: 0.12% VS males: 0.58%). Differences in the rate of seropositivity between urban areas and the rest of the country were also observed during the study period. The four-month infection fatality rate (IFR) was estimated to be 0.47%, while the respective case fatality rate (CFR) was at 1.89%. Our findings confirm low seroprevalence of COVID-19 in Greece during the study period. The young adults are presented as the most affected age group. The loss of the cumulative effect of seropositivity in a proportion of previous SARS-CoV-2 infections was indicated.

COVID-19 Outbreak on a Passenger Ship and Assessment of Response Measures, Greece, 2020

We describe response measures to an outbreak involving 128 (33.4%) coronavirus disease cases (46.1% asymptomatic) among 383 persons onboard a passenger ship. Multivariate analysis indicated that dining in certain rooms and bar areas, nationality, working department (for crew members), and quarantining onboard the ship were significantly associated with infection.

Newly Diagnosed Acute Myeloid Leukemia in a Patient With Severe SARS-CoV-2 Infection

We present a 68-year-old male patient with persistent and complicated SARS-CoV-2 infection who was diagnosed with acute myeloid leukemia (AML). The patient suffered from fever, cough and progressive dyspnea for 10 days and he was admitted to the intensive care unit due to respiratory failure and cytokine release syndrome (CRS). Despite a transient improvement of CRS by the implementation of supportive care, including also the administration of recombinant tissue plasminogen activator (rt-PA) and tocilizumab, his clinical course worsened over time. Thus, a bone marrow aspiration was performed revealing the presence of myeloblasts in a proportion of 32% and flow cytometry confirmed the diagnosis of AML-M1 according to FAB classification. Re-evaluation of peripheral blood tests revealed that the patient was admitted with anemia and thrombocytopenia that were never recovered during hospitalization. Due to the patient's poor clinical condition, no chemotherapy was applied, and he died of sepsis and multi-organ failure two days later. This case suggests that in all patients with a persistent and/or complicated infection, even during pandemics, the presence of an underlying hematologic malignancy should always be taken into consideration.

Opportunistic screening for hypertension: what does it say about the true epidemiology?

This study aimed to assess the reliability of opportunistic screening programs in estimating the prevalence, treatment, and control rate of hypertension in the general population. Two recent epidemiological surveys obtained data on hypertension in the adult general population in Greece. The EMENO (2013-2016) applied a multi-stage stratified random sampling method to collect nationwide data. The MMM (2019) collected data through opportunistic (voluntary) screening in five large cities. Hypertension was defined as blood pressure (BP) ≥ 140/90 mmHg (single occasion; average of 2nd-3rd measurement; electronic devices) and/or use of antihypertensive drugs. Data from a total of 10,426 adults were analyzed (EMENO 4,699; MMM 5,727). Mean age (SD) was 49.2 (18.6)/52.7 (16.6) years (EMENO/MMM, p < 0.001), men 48.6/46.5% (p < 0.05) and body mass index 28.2 (5.7)/27.1 (5.0) kg/m² (p < 0.001). The prevalence of hypertension in ΕΜΕΝΟ/MMM was 39.6/41.6% (p < 0.05) and was higher in men (42.7/50.9%, p < 0.001) than in women (36.5/33.6%, p < 0.05). Among hypertensive subjects, unaware were 31.8/21.3% (EMENO/MMM, p < 0.001), aware untreated 2.7/5.6% (p < 0.001), treated uncontrolled 35.1/24.8% (p < 0.001), and treated controlled 30.5/48.3% (p < 0.001). In conclusion, the prevalence of hypertension was similar with random sampling (EMENO) and opportunistic screening (MMM). However, opportunistic screening underestimated the prevalence of undiagnosed hypertension and overestimated the rate of hypertension treatment and control. Thus, random sampling national epidemiological studies are necessary for assessing the epidemiology of hypertension. Screening programs are useful for increasing awareness of hypertension in the general population, yet the generalization of such findings should be interpreted with caution.

Transmission Dynamics of SARS-CoV-2 during an Outbreak in a Roma Community in Thessaly, Greece-Control Measures and Lessons Learned

A COVID-19 outbreak occurred among residents of a Roma settlement in Greece (8 April-4 June 2020). The aim of this study was to identify factors associated with an increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and to evaluate the effectiveness of control measures implemented. Data were analyzed from individuals that were tested for SARS-CoV-2 during contact tracing, population screening or hospital visits. RT-PCR was used for the detection of SARS-CoV-2 in oropharyngeal samples. Risk factors for household secondary attack rates (SAR) and hospitalization with COVID-19 were examined using chi-square tests, Fisher's exact tests and logistic regression analyses. During the outbreak, 142 cases, 20 hospitalizations and 1 death were recorded, with a total of 2273 individuals tested. The risk of hospitalization was associated with age (OR: 1.04, 95% CI: 1.02-1.07) and Cycle threshold (Ct) values (OR for a decrease in Ct values by 1: 1.18, 95% CI: 1.07-1.31). Household SAR was estimated at 38.62% (95% CI: 32.50-45.01%). After the designation of an isolation facility for cases, household SAR declined from 74.42% to 31.03%. Household size was associated with the risk of infection (OR: 2.65, 95% CI: 1.00-7.07). The presence of COVID-19 symptoms among index cases was correlated with higher transmission (OR: 23.68, 95% CI 2.21-253.74) in multivariate analysis, while age was found to be associated with SAR only in univariate analysis. Roma communities can be particularly vulnerable to the spread of SARS-CoV-2. In similar settings, symptomatic cases are more important transmitters of SARS-CoV-2. Within these communities, immediate measures should be implemented to mitigate disease spread.

Prevalence of diabetes and pre-diabetes in Greece. Results of the First National Survey of Morbidity and Risk Factors (EMENO) study

AIMS

To report the results of the first national Health Examination Survey (HES) on the prevalence of diabetes, its pharmacologic treatment and level of control, as well as pre-diabetes in Greece.

METHODS

Data were derived from the National Survey of Morbidity and Risk Factors (EMENO), in a randomly selected, representative sample of the adult Greek population. Sampling weights were applied to adjust for study design and post-stratification weights to match sample age/sex distribution to the population. Non-response was adjusted by inverse probability weighting. Weighted prevalence estimates are provided.

RESULTS

A total of 4393 persons with HbA1c and/or fasting plasma glucose measurements were included. Total diabetes prevalence was 11.9% (95% CI: 10.9-12.9), known diabetes 10.4% (9.5-11.4), and unknown 1.5% (1.1-1.9), with considerable increase in older age groups and no difference between genders. Pre-diabetes prevalence was 12.4% (11.4-13.6). The majority of persons with known diabetes were receiving metformin. Of those with known diabetes (and measured HbA1c), 70.9% were well controlled (HbA1c <7.0%).

CONCLUSIONS

This first representative national HES showed high prevalence of diabetes in Greece, with low prevalence of unknown diabetes. Pre-diabetes prevalence is also substantial. These results will hopefully enable national authorities develop tailored and efficient strategies for disease prevention and management.

Evaluation of Two Chemiluminescent and Three ELISA Immunoassays for the Detection of SARS-CoV-2 IgG Antibodies: Implications for Disease Diagnosis and Patients' Management

The estimation of anti-SARS-CoV-2 IgG antibodies is possibly the best approach to accurately establish the number of infected individuals and the seroprevalence of COVID-19 within a population. Thus, several commercial immunoassays have recently been developed. The purpose of our study was to assess the performance of five commonly used immunoassays in Greece (3 ELISA, namely Euroimmun SARS-CoV-2, GA GENERIC SARS-CoV-2 and Vircell COVID-19; and 2 chemiluminescent, namely ABBOTT SARS-CoV-2 and ROCHE Elecsys Anti-SARS-CoV-2 test) for the detection of anti-SARS-CoV-2 IgG antibodies. Sera specimens derived from 168 individuals were utilized to assess the specificity and sensitivity score of each assay. Among them, we included 99 COVID-19 patients (29 asymptomatic, 36 with symptom onset 4 to 14 days before serum sampling, and 34 with symptom initiation ≥ 15 days ago), and 69 volunteers with sera specimens collected prior to the SARS-CoV-2 outbreak and maintained at −80°C. We demonstrated that chemiluminescent immunoassays exhibit a significantly higher specificity score but a lower sensitivity, compared to ELISA immunoassays. Moreover, immunoassays detecting IgG antibodies against SARS-CoV-2 N protein instead of S protein alone are more reliable, considering both specificity and sensitivity scores. Interestingly, all asymptomatic patients displayed anti-SARS-CoV-2 IgG antibodies, confirmed by at least two immunoassays. We suggest that chemiluminescent assays could be used as screening methods for the detection of anti-SARS-CoV-2 antibodies to evaluate the possible prevalence of disease in the general population, while ELISA assays would be more reliable to evaluate, and follow-up confirmed COVID-19 patients.

West Nile virus in humans, Greece, 2018: the largest seasonal number of cases, 9 years after its emergence in the country

Background

Human cases of West Nile virus (WNV) infection are recorded since 2010 in Greece, with seasonal outbreaks occurring almost annually. Enhanced surveillance has been implemented since 2010, to promptly characterise cases’ temporal and geographical distribution and inform authorities for implementation of appropriate measures (mosquito control, health education, blood safety).

Aim

We describe the epidemiology of WNV human infections in Greece focusing on the 2018 season.

Methods

The National Public Health Organization advised physicians to test all suspect WNV infection cases and refer samples to reference laboratories. Laboratories notified diagnosed cases on a daily basis. Treating physicians, patients, and infected blood donors were interviewed within 48 hours after diagnosis and the probable infection location was identified. Hospitalised cases were followed up until discharge.

Results

A total of 317 autochthonous WNV infection cases were diagnosed in 2018. Among them, 243 cases had neuroinvasive disease (WNND), representing a 23% increase of WNND cases compared with 2010, the previous most intense season. There were 51 deaths. Cases started occurring from week 22, earlier than usual. Both rural and urban areas were affected, with 86 (26% of the total) municipalities belonging to seven (54% of the total) regions recording cases. Two major epicentres were identified in Attica and Central Macedonia regions.

Conclusions

The largest number of human cases of WNV infection ever recorded in Greece occurred in 2018, with a wide geographical distribution, suggesting intense virus circulation. Enhanced surveillance is vital for the early detection of human cases and the prompt implementation of response measures.

Nationwide Survey in Greece about Knowledge, Risk Perceptions, and Preventive Behaviors for COVID-19 during the General Lockdown in April 2020

Background: The aim of this study was to investigate the knowledge, attitudes, and practices of the Greek general population toward coronavirus disease 2019 (COVID-19) during the lockdown period in April 2020, to examine factors associated with misperceptions and to determine behavioral patterns that may require interventions. Methods: A cross-sectional study of the general Greek population (N = 1858) was conducted. A geographically stratified cluster sampling was implemented. A questionnaire was composed consisting of 35 questions. Data collection took place from 15 April to 2 May 2020. A random-digit dialing survey was conducted by 29 interviewers. Results: The majority of respondents (62.7%) answered ≥12/17 questions correctly. Participants aged 18–44 years, male gender, specific occupations (freelancer, unemployed, housewife, retiree) and those who sought information about COVID-19 from less than two sources received lower aggregated scores on knowledge questions. Regarding attitudes toward future vaccination, 18.9% declared that were against it, while 81.1% that they may consider or will be vaccinated. About 40% were not using a face mask and only 42% washed their hands appropriately. Conclusion: Adjusting information campaigns targeting especially people below 45 years of age can help to sensitize them and realise their role to control the spread. Further targeted surveys are needed to adjust/design prevention campaigns.

Nationwide Study on Practices Related to Screening Among Greek Paediatricians

Objective

The aim of this study was to investigate pediatricians' practices toward screening in Greece.

Materials and Methods

The survey was conducted within a six month period in a stratified random sample of 371 pediatricians. A questionnaire with three sections was created and pilot tested. Socio-demographic characteristics associated with inappropriate screening were identified using multivariable logistic regression models and latent class analysis.

Results

A total of 294 participants completed the telephone survey (response rate 78.6%). The median number of wrong answers to questions related to pediatricians' practice towards screening recommendations was 7±1.57 with minimum 2 and maximum 11 wrong answers. Pediatricians, with less than 15 years of experience, age >50 years old or view more than eighty patients per week, have had significantly higher odds of responding wrong to more than seven questions, hence be less compliant to USPSTF screening guidelines. Latent class analysis has shown that female gender, age <50 years old, and work in the private sector, were associated with a poor practice towards international screening guidelines.

Conclusion

Our survey found gaps in screening practices among a nationwide sample of Greek pediatricians. Moreover considerable variability in reported practices of screening was noted. There is a need for the development of a national childhood screening program in Greece.

Detection of imported COVID-19 cases worldwide: early assessment of airport entry screening, 24 January until 17 February 2020

The purpose of this study was to provide an overview of entry screening measures applied at airports in response to the COVID-19 epidemic worldwide. Between 24 January and 17 February 2020, 5.2% (95% CI 3.1–8.5) of the 271 total imported COVID-19 cases worldwide (excluding imported cases arriving in China, Macao, and Hong Kong) with known detection location were captured through airport entry screening. The majority of imported COVID-19 cases (210) were identified by the health care system (77.5%). Efforts should focus on health care system preparedness for early case detection, since according to our and previous studies health care facilities are the actual point of entry of imported cases.

Educating, training, and exercising for infectious disease control with emphasis on cross-border settings: an integrative review

INTRODUCTION

Points of entry and other border regions educate, train, and exercise (ETEs) their staff to improve preparedness and response to cross-border health threats. However, no conclusive knowledge of these ETEs' effectiveness exists. This study aimed to review the literature on ETEs in infectious disease control concerning their methods and effect, with an emphasis on cross-border settings and methods that enlarge ETEs' reach.

METHODOLOGY

We systematically searched for studies in the databases Embase, Medline, Web of Science, PsycInfo, ERIC, and Cinahl. After successively screening titles and abstracts, full-texts, and citations, 62 studies were included using in- and exclusion criteria. Data were extracted using a data-extraction form. Quality assessment was performed. We developed a theoretical framework based on which we analyzed the ETE context (target group, recruitment, autonomy, training needs), input (topic, trainers, development and quality of materials), process (design, duration, interval, goals), evaluation (pre-, post- follow-up tests), and outcome (reaction, learning, behavior, and system).

RESULTS

We found a limited number of published evaluations of ETEs in general (n = 62) and of cross-border settings (n = 5) in particular. The quality assessment resulted in seven ETE methodologies and 23 evaluations with a 'good' score. Both general studies and those in a cross-border setting contain a low-moderate detail level on context, input, and process. The evaluations were performed on reaction (n = 45), learning (n = 45), behavior (n = 9) and system (n = 4), mainly using pre- and post-tests (n = 22). Online learning methods have a high potential in enlarging the reach and are effective, particularly in combination with offline training. Training-of-trainer approaches are effective for learning; new ETEs were developed by 20-44% of participants until six months after the initial training.

CONCLUSION

Our study reveals a limited number of publications on ETEs in infectious disease control. Studies provide few details on methodology, and use mainly short-term evaluations and low level outcomes. We call for more extensive, higher-level evaluation standards of ETEs, and an easy and sustainable way to exchange evaluations within the workforce of infectious disease control in cross-border settings. The theoretical framework developed in this study could guide future development and evaluation of ETEs in infectious disease control.

Repeated leftover serosurvey of SARS-CoV-2 IgG antibodies, Greece, March and April 2020

A serosurvey of IgG antibodies against severe acute respiratory coronavirus 2 (SARS-CoV-2) was performed during March and April 2020. Among 6,586 leftover sera, 24 (0.36%) were positive, with higher prevalence in females, older individuals and residents of large urban areas. Seroprevalence was estimated at 0.02% and 0.25%, respectively, in March and April, infection fatality rate at 2.66% and 0.54%. Our findings confirm low COVID-19 incidence in Greece and possibly the effectiveness of early measures.

Environmental contamination of SARS-CoV-2 on surfaces, air-conditioner and ventilation systems

Background

COVID-19 can be transmitted directly through respiratory droplets or indirectly through fomites. SARS-CoV-2 has been detected on various environmental surfaces, air samples and sewage in hospital and community settings.

Methods

Environmental samples were collected from a ferryboat during a COVID-19 ongoing outbreak investigation and a nursing home and from three COVID-19 isolation hospital wards and a long-term care facility where asymptomatic COVID-19 cases were isolated. Samples were tested by real-time reverse transcriptase–polymerase chain reaction.

Results

SARS-CoV-2 was detected on swab samples taken from surfaces of food preparation and service areas, hospital isolation wards, an air exhaust duct screen, air-conditioning filter, sewage treatment unit and air sample during investigations conducted in response to COVID-19 outbreaks on a ferryboat, nursing home, isolation facility and COVID-19 hospital wards.

Discussion

Food preparation areas and utensils can be contaminated during COVID-19 outbreaks. Respiratory droplets/nuclei from infected persons can be displaced by the air flow and deposited on surfaces. It can be assumed that in the same manner, air flow could transfer and deposit infected respiratory droplets/nuclei from infected persons to the mucous membranes of persons standing against the air flow direction.